The purpose of the NHANES (National Health and Nutrition Examination Survey) Epidemiologic Follow-up Survey is to conduct a longitudinal study of 14,407 adults originally surveyed in 1971-1975, to investigate subsequent health and mortality outcome. Respondents will be traced and re-examined. Information will also be obtained from hospital records, the National Death Index and death certificates. The NHANES Follow-up Survey is well under way in the field. The purpose of this intramural project is to examine the relationship of chemopreventive and nutritional factors and cancer in the very large representative population which NHANES offers. It provides an opportunity to examine these factors and potentially confounding or modifying factors in a prospective fashion, and to examine the effectiveness or toxicity of some dietary agents which are currently of great interest for cancer prevention. The relationship of baseline vitamin use, biochemical or nutritional measures and subsequent health status will be examined. In addition, descriptive data and trends in potential risk factors or protective factors over time will be examined. The project will involve the recoding of certain baseline data, and the specification of an analysis plan to examine the relationships and trends described above. The National Center for Health Statistics will conduct preliminary analyses, and will participate with DRCCA in the development of more advanced analyses of these data.